Surprising Convergence of Day and Night Upper-Atmosphere Temperatures

A cursory review of articles about the upper atmosphere reveals many theories about the role of CO2 on temperatures aloft. By “Upper Atmosphere” we mean the region above the surface and below 100,000 feet. Actually, in this article, we will only concern ourselves with the region from 850 millibars to 100 millibars, which is about 5,000 feet to 55,000 feet.

In the early days of Global Warming, the theories predicted that the upper atmosphere would heat due to increases in CO2. Well, that didn’t happen. One recent article by NASA says that the Thermosphere (above 100,000 ft) has cooled in recent years due to decreased solar activity and a reduction in ultraviolet light. That certainly seems reasonable. Another article stated that if the lower atmosphere warms, the upper atmosphere must cool, which makes no sense to me.

Other articles posit that as CO2 increases the level at which radiation escapes to space also increases and the upper atmosphere warms. That also made no sense to me.

I decided to take a look at temperatures aloft and reasoned that the difference between day and night temperatures in the upper atmosphere might reveal whether the nighttime atmosphere is cooling faster or slower than in previous years. If cooling slower the temperature curves at 00z and 12z would tend to converge and if cooling faster the curves would diverge. Simple, right?

Upper air data was obtained from NOAA at https://ruc.noaa.gov/raobs/ for the period 1970 through 2016. The NOAA site houses balloon data in different formats but only the standard levels of 850, 700, 500, 400, 300, 250, 200, 150, and 100mb data were used. It was felt that the best way to test the hypothesis was to use data from an upper air station where moisture levels were low in the belief that a lot of moisture would cloud the results.

Initially, Tucson was selected for its dry climate and where the 00z and 12z observation times coincided with the time of maximum and minimum temperatures at 5 pm and 5 am at that location. After downloading the data as yearly files, a computer program averaged all 00z and 12z observations for each mandatory level.

The results from plotting Tucson average yearly 0000z and 1200z temperatures at different heights were unexpected, to say the least.

Figure 1. Tucson 850mb (about 5,000 ft.) temperature graph.

As expected, the 12z curve (green) shows that the air cooled during the night on average about three degrees through 1995 and then narrowed to only two degrees through 2016. Both curves are trending upward and beginning in the mid-90s the curves tend to converge, which may support the Global Warming theories since CO2 cools slower than air. However, that would mean that Global Warming did not start until the mid-90s, which is an unlikely scenario.

Figure 2. At 700mb (10,000 feet) the temperature continues to increase as the convergence of the curves becomes more pronounced beginning in 1996.

Figure 3. At 500mb (18,000 feet) the curves became virtually the same beginning in 1996.

The question must be asked, “What happened in 1996?” El Nino was in 1997 and 1998. When this graph was created, my initial reaction was that there was a serious error in the data or the extraction program. I have been unable to find such an error.

The strangeness continues with the following charts.

Figure 4. At 400mb(24,000 ft).

We are now above 90% of the moisture, and any changes in the divergence of the two curves must be due to external forces. It is unreasonable to think that a steadily rising CO2 would suddenly make itself known in this way. The following charts are included to show that the converging curves are present at all upper levels.

Figure 5. 300mb.

Figure 6. 250mb.

Figure 7. 200mb.

Figure 6. 150mb.

Figure 7. 100mb.

As can be seen in the preceding charts something happened in 1996 that affected the atmosphere beginning at 850mb and increased in severity as we go aloft, culminating in a rather large drop in temperature at 100mb. There are two things about the preceding charts: 1. the temperature, after convergence, on each chart from 300mb and higher, cool until the curve is flat at 100mb and 2. There is little change in the curves before 1996.

The NASA article said that the Thermosphere has cooled due to a reduction in ultraviolet light from a quite sun. Perhaps it is affecting lower levels also.

Figure 8. Tucson 100mb temperature and sunspots offset by three years.

If we plot the 100mb Tucson temperatures with a three-year delay of sunspots, the graph above is the result. The correlation between sunspots and the 00Z temperature is .44.

Normally we tend to think that conditions in the lower atmosphere affect the upper atmosphere, but the charts indicate that it is the other way around and the upper atmosphere is affecting the lower levels, and that is why the biggest change is not at 850mb but at 100mb where significant cooling has taken place.

To check for errors the daily data for the years 1995 and 1996 were plotted as shown below. In these two examples, there are less than 365 observations because of missing data at the 100mb level.

Figure 9. 1995 Daily Temperature for Tucson.

Figure 10. 1996 Daily Temperature for Tucson.

This error check does show that the temperature does indeed cool in the first half of 1996 as compared to 1995.

As stated earlier, Tucson was chosen because it was dry and the observation times were ideal. But to me the temperatures changes were very unusual and to investigate further, I obtained rawinsonde data for Anchorage, Alaska, and the charts are shown below. While not as dramatic as the temperature changes for Tucson, the Anchorage charts also show a rather abrupt change in temperature, but not in 1996 but 1999. Again the biggest change was with temperatures at 100mb.

Figure 11. Anchorage 850mb.

Note how the two curves on Anchorage’s 850mb chart are much closer than the same chart for Tucson. I believe this is due to much greater water vapor in the air over Anchorage compared to Tucson. Also, the times of observation are at 3 am and 3 pm, which is not ideal but not bad either.

Figure 11. Anchorage 100mb.

While the 100mb data for Anchorage is cooler in later years, it does not have the pronounced cooling as seen in the Tucson chart and convergence occurs in 1999 as opposed to 1996 for Tucson. Anchorage charts for levels between 850mb and 100mb are not shown but are available if anyone is interested in them.

Figure 11. Spokane 100mb Temperature.

Only the 100mb chart is shown for Spokane. Note cooling in later years and the convergence started in 2006.

Figure 12. Hilo, Hawaii 100mb.

And here is Hilo Hawaii where the temperatures converged in 2011.

So now we have Tucson temperature aloft curves converging in 1996, Anchorage’s in 1999, Spokane’s in 2006, and Hilo’s in 2011.

· Tucson’s 100mb temperatures are increasing until about 1990, drop sharply until they converged in 1996 and then remain constant.

· Anchorage’s 100mb temperatures drop until about 1996, increase slightly and converge in 1999 and almost constant after that.

· Spokane’s 100mb temperature is decreasing after 1982 and then converging in 2006 and remaining constant after that.

· Hilo’s 100mb temperature curve is rather constant until it converges in 2011 and drops sharply in 2014.

These graphs raise many questions and provide few answers. Whatever the cause of cooling temperatures at the 100mb level, it is not directly related to steadily increasing CO2. It is apparent that the phenomenon is worldwide and it starts at the higher levels.

As a further check, El Paso data was used as shown in the following graph.

The plots for El Paso were almost identical to Tucson’s and also has a correlation of 0.44.

The following conclusions are pure speculation.

The sun is the main driving force for changes in temperature at high altitudes, less so for high latitude locations. It is clear that the sun is changing the temperature at high altitudes, but what about the convergence of night and day temperatures?

Occam’s Razor says that the simplest answer is usually correct, which means that the sun is causing both. And indeed the answer is simple. Consider that normally the radiation from the sun passes through the atmosphere without heating it and all the heat in the upper air comes from below as long wave radiation. But if ultraviolet radiation is heating the upper atmosphere, we have a different kettle of fish. Since prior to the sun becoming quiet the upper atmosphere was being heated during the day, that extra heat would be dissipated at night, but without that heating, the night temperature stays the same as the day temperature.

Charles Samuels, It IS interesting that the data seems to change after 1996. But, this article is premature, superficial, and highly speculative. You don’t seem to understand some of the arguments for why different parts of the atmosphere might heat or cool, which means you did not do your homework. This is the kind of article that WUWT should tell the author to go back and revise and resubmit. When I see data like that, I immediately wonder if it is due to a change in how it was measured (instrument/technology, etc) or in how it was processed. Again, one needs to do more homework before coming up with theories and random “explanations”. And randomly shifting sunspot data for some type of lag, also premature if you have not ruled out instrument or processing changes.

I read the article as Mr. Samuels merely posting what he discovered from the data, not the end all, be all. A good start to some grad students’ papers doing more investigation maybe. What do you expect here, a fully funded 5 year investigative study?

This is a website where people put up interesting findings around climate related subjects, not a frigg’n repository for PhD thesis. WTF

I agree that the article does not seem to show much evidence of basic research and background reading.

Another article stated that if the lower atmosphere warms, the upper atmosphere must cool, which makes no sense to me.

Well since we don’t get to know which “another ” this was or what it actually said, there’s not much scope for trying to explain why it said that or whether it was correct or not. I suspect the author’s resume of what it said is probably confused. Please supply refs, citations and quotes.

It may have been saying the opposite: that a cooling stratosphere implies a warming troposphere. That does seem to happen:

If the author is confused by that, it probably just reflects a lack on understanding of climatology.

By “Upper Atmosphere” we mean the region above the surface and below 100,000 feet.

Well if it starts at the surface, why is it called UPPER atmosphere? Who defines it in that way apart from the author?

@billw1984
Every advance in human knowledge begins with someone thinking “I wonder…” Not everyone who gets the ball going has the science “chops” to get it across the goal line, but that does not lessen their contribution.

The ‘convergence’ issue seems quite odd. But in view of the constant “bias correction” which seems to be de rigeur in climate science, the first step is to study the meta data and documentation of the data sets. That is the FIRST step. Don’t spend time head scratching until you have checked there is not an obvious observational method change or some data ‘correction’ going on.

Quite possibly an equipment change which happened in different years at different sites.

“Don’t spend time head scratching until you have checked there is not an obvious observational method change or some data ‘correction’ going on.

Quite possibly an equipment change which happened in different years at different sites.”

In other words, it may be as useless as the altered historical surface data?
Someone please correct me if I am wrong, but is this radiosonde data the same information that is elsewhere referred to “balloon data”?
As in the balloon data sets that are used in many graphs, and that tend to show that the alterations to the surface temperature records and the GCMs are diverging from reality, as compared to satellite data?

And again, correct me if I have this wrong, but is it not the case that the balloon data is used to calibrate the satellite data?

Has someone cleverly found a way to cause the satellites data sets to show warmer temps than are actually occurring?

Step one in science is to make an observation. Looks like he has done that! If you see nothing there of interest, move on. If others see something, they can pursue it.
This isn’t Warmia, where we look in cracks and crevices and put on special glasses to see what we are already convinced is there!

Start your own blog billw1984 and then you can determine what is suitable for YOUR blog. This is not your blog and your declaration of what is or is not suitable for posting here is irrelevant except for what it reveals about you.

The convergence is not likely caused by instrument change since Spokane convergence was 10 years after Tucson and Hilo’s 15 years after Tuscon. Unless those two sites had a warehouse of instruments to use up.

Anyone else think it is weird that the more northerly locations had a warmer temperature than the more tropical locations?
Hilo over the tropical Pacific is far coder than it is over Anchorage.
Howcumzit?

I have read some comments and discussions here on meridional airflow and wandering” jet streams. Here in Western Canada we are having a fairly cool, wet and windy spring and early summer. Reminds me very much of the 70’s. The increased winds especially as I have noted over many years now that we don’t get nearly as much wind as we used to. These exaggerated jet stream patterns make for quite variable weather and more winds as system stack closer together on and between jet stream flows.My 2 cents worth.

Water vapor cools the troposphere. Strong thermals near the equator cause water vapor to rise higher which causes the colder temperatures. Over Anchorage, the thermals are much weaker and the upper troposphere is warmer.

The upper atmosphere isn’t a fixed height above the Earth. It’s where the the atmosphere starts heating with height instead of cooling. That is, it’s where the ozone lives – the stratosphere. And the stratosphere is at a much higher altitude on the Ecliptic plane – or the “Equator” – where the Sun rays are perpendicular to the atmosphere – than is it at the poles – and much thicker. The stratosphere is close to surface at the poles but much thinner. The Sun’s UV radiation drives ozone production. In short, you need measure the temperature to find the boundary between the troposphere and the stratosphere. The tropopause is like spring – it’s somewhere between two extremes.

if ultraviolet radiation is heating the upper atmosphere, we have a different kettle of fish. Since prior to the sun becoming quiet the upper atmosphere was being heated during the day, that extra heat would be dissipated at night, but without that heating, the night temperature stays the same as the day temperature.

Given that raobs are only launched a couple of times a day (or were when I did my PhD), I think the chances of getting a raob observation before, during, and after any specific time on any specific date are quite low. Good luck hunting.

You could plot the Ozone levels at those heights and locations to compare to the temps.
But you must have the actual moisture as well, because it controls actual energy in the system, more so than the air. Don’t forget the Cosmic Ray theory.
I assume that all the temps are Raw Data.

You are using unadjusted radiosonde data from IGRA. Maybe you have found breakpoints caused by change of radiosonde types. Newer ones are typically less sensitive to spurious solar heating, and unadjusted, the merged timeseries would get a spurious cooling after the change..

So real data has to be “adjusted” in order to not be “spurious”?
That sounds like doubletalk to this kid.
Daytime temps are warmer, and it is also when any solar heating would happen, which would make it warmer still, and so the temps would diverge, not converge.
The same goes for radiative cooling at night if there is no shielding or insulation to ensure that what is being measured is the actual air temperature.
And as for that, if these things are not shielded or insulated in some way to ensure they are actually measuring the air temp, the readings would be as useful as a bare thermometer mounted on a pole and used to measure the surface temp.
IOW…worthless.
Maybe someone who has some actual information could explain exactly how these devices are set up, so as to ensure a reading of air temp is what is being recorded?

My first thought too, just a suspicion, but need to be checked out and eliminated before going further. There is indeed a “look” to the data that suggest this. Have seen it before when an instrument went out of calibration, internal capacitor went o/c, didn’t stop the thing working so no alert just made results as indicated wrong.

I meant to add that detection of strange effects is often helped by use of formal, proper error analysis and confidence limits. These fundamental measures are done poorly or not at all in too much climate work. Geoff.

Looks to me like someone had budget cuts, instead of balloon data twice a day, runs it once, and replicates it for the other part of the day as certain software programs probably search for both records so one cannot just be omitted. Some runs twice a day with limited cutbacks would show a “convergence trend”.
Else check for volcanic eruption dust.

Air without IR emitters will never cool. It is actually the “greenhouse” gases that cool the air.
Below the tropopause, water vapor is the main cooling gas.
From the tropopause to the mesopause, CO2 is the main cooling gas.
The thermosphere is hot mainly because there are very few IR emitters.

Over the time period studied, the radiosonde instrumentation changed – a lot.
It was tube based, now it is solid state.
It is highly likely that the convergence after a specific date is a result of that.
Unfortunately, I can not quickly find a list of dates,
but this file shows major changes in 1931, 1983, 1999, 2003.
Because of logistic issues, I would not assume that all sites update their radiosondes in the same year.

100 mb is only about 16km, which is either in the tropopause or just above it depending mostly on the latitude.
As a result, water vapor may still play a significant role as will the jet stream.

The instrumentation changed? Then would that mean the daytime/nightime temperatures were always nearly the same and we didn’t know? Or the new instrumention is not measuring accurately and the temperatures are not converging.

funny how all the actual historic temperature data records are corrupted with sites moves or instrument changes or unicorn discharges or whatever excuse is used to justified “adjusting it” … any adjusted data before the satellite record is unfit for purpose other than grant funding fraud …

Daytime/nighttime differences in balloon-temperature measurements are a known artefact related to daytime solar heating. There is plenty of scientific literature on daytime/nighttime differences and (long term) biases in sonde temperature profile measurements, including tables for applying temperature corrections.

But if ultraviolet radiation is heating the upper atmosphere, we have a different kettle of fish.

It has been known for quite some time that the ozone layer in the atmosphere intercepts solar UV and is responsible for the temperature inversion in the stratosphere.
see eg https://en.wikipedia.org/wiki/Ozone_layer

“Consider that normally the radiation from the sun passes through the atmosphere without heating it..”

Water vapour absorbs fair amounts of solar near infrared, which heats it. Upper tropospheric water vapour has reduced, which while lower-mid tropospheric has increased. With the shift being from 1995-96, it should related to the global multidecadal AMO signal.

Solar radiation in the x-ray and uv bands below about 170 nm is nearly completely absorbed within the thermosphere. That is the main reason why it is so hot.
The ozone layer is much lower down, in the lower stratosphere, and absorbs uv in the 200-315 nm range, but not all of it. Some gets through.

Another article stated that if the lower atmosphere warms, the upper atmosphere must cool, which makes no sense to me.

One theory would be that the lower atmosphere is warming because CO2 is keeping the heat from escaping. That would mean the upper atmosphere receives less heat from below and therefore cools. It’s more complicated than that. WUWT

The question was why the upper atmosphere would cool as the lower atmosphere warms. What I wrote is a paraphrase of the ‘conventional’ explanation. The provided link shows that the situation is complicated and not all that well understood.

The ‘pause ‘ exactly coinciding with the global crash and slow down of the world economy and a dramatic reduction in the rate of rise of air traffic… Contrails inject water vapour that modulates albedo at very high levels: up to 50,000 feet.

Perhaps I have misunderstood, but if you’re saying that contrails increase albedo and thus reduce surface warming by increasing reflectivity, then, all other things being equal, shouldn’t we expect to see an ‘increase’ in surface temperatures during periods of reduced aircraft movements (i.e. more UV radiation reaching the surface)?

The same would go for any reduction in industrial output (aerosols) associated with a downturn in economic activity. Surface temperatures should have gone up, not down, shouldn’t they?

I agree, it’s probably not the albedo. Water vapor is the most important greenhouse gas. If you inject water vapor, especially at an altitude where there isn’t much in absolute terms, there should be an increased greenhouse effect.

Visible contrails mimic clouds.

They found that contrails depress the difference between daytime and nighttime temperatures, typically decreasing the maximum temperature and raising the minimum temperature. In this respect, the contrail clouds mimic the effect of ordinary clouds. link

The other thing with Leo’s observation is the five year lead. When air traffic halted after 911, the effect due to the lack of contrails was immediate.

Leo could be onto something but I have a nasty feeling that it’s complicated.

I’d actually like to see the graph, the data sources and the time period involved.

I think commercial air traffic may have been a factor in the 60 and 70’s cooling and that El Chichon and Mt Pinatubo aerosols provoked a purging of the build up of pollution in the stratosphere as well as ozone destruction. This lead to stratospheric cooling and tropospheric warming.

If planes are causing global warming, then someone better tell those globe hopping jackasses like Leonardo Di Caprio, and the 40,000 who fly around for various climate conferences!
Oh, if anything would make me laugh really long and hard it would be finding out this is a fact.

Anyways, the sort of air traffic which produced a lot of contrails really began to ramp up during and after WWII. And this period was marked by thirty years of global cooling. As long as you use actual data, not the mush that they altered it into recently.

Ouch, limiting air traffic to below 15,000 ft would cause a real crimp in air traffic in both higher fuel costs (far more drag and weather) as well as congestion. The range of commercial flights would be severely diminished and the ride would be much rougher. There is a real advantage to getting up where the air is cold and thin as well as being above almost all weather. I doubt very much if trans-oceanic flights would be economically viable at those altitudes.
At 35,000 ft the air density is less than half of that at 15,000 ft.

As many corporate and private jet operators found out to their dismay during the ATC strike of 1981. Unable to get IFR clearance to fly above 18,000 feet they were forced to fly VFR at 17,500 and below, resulting in nearly double fuel costs. Non-stop transcontinental trips, such as JFK to LAX or SFO, normally easy for a Jetstar or G2 of the day became impossible, requiring a mid-continent fuel stop for even greater expense and lost time. Might as well recommend going back to the DC-3 and Pan-Am Clippers as suggest a 15,000 foot ceiling.

As corporate and private jet operators found out to their dismay during the 1981 US ATC strike. Unable to get an IFR clearance required to fly above 18,000 feet, they were often forced to fly at 17,500 and below resulting in a considerable increase in fuel burn per hour and a much slower airspeed, more than doubling the fuel cost per trip. Non-stop transcontinental flights such as JFK to LAX or SFO, normally easy for the Jetstar and G-2 of the day became impossible requiring a mid-continent fuel stop for even more expense and lost time. With a 15,000 foot ceiling the longer intercontinental flights would not just be uneconomical, they would be impossible. Might as well recommend going back to the DC-3 and Pan-Am China Clippers as a 15,000 foot ceiling.

Contrails might reflect light back to space but they don’t “inject” water vapour into the atmosphere. They are a pressure drop effect on existing water vapour. The jet engine exhaust does inject water into the atmosphere. Not sure what effect that or the contrails might have. I suspect that with the majority of people living in urban areas where flights originate and terminate, this seems more important than it really is. Most of the planet doesn’t really see a lot of jet traffic.

“Most of the planet doesn’t really see a lot of jet traffic.”
Significant portions of several continents do, however.
Remember the effects noted after 9/11 when air traffic was grounded?

Modern jets burn fuel very efficiently I think, and it is all converted to w.v. and CO2.

Lets look a few things up…

OK, a 747 burns 5 gallons per mile, and a gallon is about 6.5 -6.8 pounds.
Hmmm…better go metric…I sense Avagadro’s number rearing it’s head soon…

Ok, that’s 12 liter per kilometer, and about 0.75-0.84 kg/liter.
So that about 9.6 kg/kilometer.
or 9600 grams/1000 meters
or about ten grams per meter, very roughly.
Jet fuel is likely mostly alkanes, having a general formula of C^n H^2n+2.
Hmmm…that gets tricky…lets just look up exhaust gasses…
Hey, I found a shortcut, but I was on the right track:

” Persistent contrails are ice clouds, so they are mostly made of ice. They also are likely to contain aircraft exhaust products (including soot and dissolved gases like sulfur dioxide) , but they are overwhelmingly made from moisture condensed out of the surrounding air. In one example reported by Knollenburg (October 1972, Journal of the Atmospheric Sciences, Pages 1367-1374), the amount of moisture released by the burning of jet fuel from a research aircraft was 1.7 grams of water for every meter of flight path. However, the total water measured in a persistent contrail produced by the aircraft was conservatively measured (that is, it was likely an underestimate) to be between 20700 to 41200 grams of water for every meter of the contrail path! Nearly all of the contrail is created from the moisture in the atmosphere…”

So John, you are correctamundo!
Contrails contain a little water from exhaust, but the vast majority is from the w.v. of the air they are travelling through.
Maybe one part in 10,000 or less is from the exhaust!
This should have been easy to guess…they do not form unless the air is nearly saturated to begin with.
But I love a good calculation.
(car exhaust contains roughly equal percentages of w.v. and CO2, but i did not get to the part about whether that was by weight or my volume…water is very light compared to CO2, and only the hydrogen is from the fuel)

Yes, here in South Florida they generally do not form, and if they do they do not persist long.
Up near Jacksonville I used to see them all the time, and occasionally in Orlando.
Just about never see them here…and there are a lot of planes flying over.

The water vapor per cubic meter over the Antarctic at 32 km is around 1e-4 grams per cubic meter. tables 2,3,4,5 So, the airplane adds enough water to double the vapor in 1e5 cubic meters. That’s a lot.

In the early days of Global Warming, the theories predicted that the upper atmosphere would heat due to increases in CO2. Well, that didn’t happen. One recent article by NASA says that the Thermosphere (above 100,000 ft) has cooled in recent years due to decreased solar activity and a reduction in ultraviolet light.

Very interesting analysis. Something is clearly going on. This raises a few questions for me:
1 what is the significance?
In other words is this impacting weather or life?
2 why is the simplest answer the sun and not CO2?
Thanks

I would love to point to my much more casual approach, which of course is about more fundamental aspects of climatology. This is about (night time)cooling patterns relative to the sky condition (that is cloudiness).

It is based on data from the years 2015 and 2016, in this case Parkersburg, WV. (I have done a lot of other places too). 0 to 8 represents the average cloudiness throughout the night, with 0 meaning all clear, and 8 all overcast. Also I added the sample size, that is the number of nights within each category.

Could you possibly imagine how these data could help to identify the magnitude of cloud forcing?

With no clouds it only cools three one hundredths of a degree in 61×10 minutes at night?
How did you measure that amount of cooling?
Anyplace I have lived, the rate of nighttime cooling on cloudless nights depends a lot on the surface humidity levels, and how much if any wind there is.
In Florida, with low humidity and light winds, the temp can drop ten degrees or more in an hour.
And during a radiational cooling event like that, a light veil of cirrus blowing in from the Gulf can cause temps to rise several degrees in a matter of minutes.
I spent many years engaged in highly temperature sensitive commercial agriculture…and watching the temp at night from October to April was often an all night dealio.

Well more like over 3/100s of about 288K, that is about 10K. And yes, anything could happen, which is why we take average values, so that we do not need to bother with unique weather events. Your reasoning is not too reasonable..

Anywho, getting to your original question Erich, which is an important one, nighttime data by itself seems unlikely to give an accurate answer.
Because clouds have the different effects depending on the type of clouds, and whether it is day or night, and a lot of other stuff most likely.
I think increased water vapor leading to increased amounts of clouds are likely to cause net cooling, and that this is why and how the Earth has had a stable enough temp for hundreds of millions of years to let complex life flourish on the surface.
No matter what has happened…huge impacts, gigantic outpourings of lava, widely varying amounts of various atmospheric constituents…

Could I suggest a glance at WUWT’s own reference page for global temperature , and in particular the charts for Lower Troposphere(TLT, Middle Troposphere , (TMT), Troposphere/Stratosphere(TTS) and Lower Stratosphere (LTS).
Ignore the trend lines and look at the slopes before 2000 and after 2000. For TLT and TMT the slope pre 2000 is positive(warming) , followed by a level “pause”. For TTS it is fairly level pre -and post- 2000. For LTS it is negative (cooling) pre 2000 , but constant thereafter .
Is this a globally averaged confirmation of the locally specific , more detailed analysis , of the original posting?
It is interesting to see how volcanic effects and el Ninos have opposite effects in both lower and upper regions of the atmosphere – and how much more significant they are (if temporary) than the underlying trends , be those of natural or anthropogenic origin.

When it is cold outside, I must add energy/heat to my house to keep it warm inside. When it is hot outside, I must add work to move energy/heat from inside the house back outside by using an air conditioner.

Energy moves by itself from high energy/temperature to low energy/temperature. Energy cannot move from low energy/temperature to high energy/temperature without adding work.

Is it hot out in space or cold?

The space station out there in space has a sophisticated radiative cooling system to move excess energy, i.e. adding work, from inside to outside. If space is cold, why is that needed?

A luminous photosphere of energy radiates from our sun in all directions out across the cosmos. When that sphere expands to the average orbital distance to the earth its dispersed luminous surface radiates a power flux of 1,368 W/m^2, aka the solar constant, with a S-B BB equivalent temperature of 390 K, 17 C higher than the boiling point of water under full atmospheric pressure. That’s hot.

Without an atmosphere the surface of the earth would be much like that of the moon, barren, dusty, pock marked, blazing hot on the lit side, sub-sub-sub-freezing cold on the dark side.

Interesting.
The moon, which is famously airless, has half lit by the sun and hot, and half in the dark and cold.
It is reported that the average temp on the lit side is about 107C, and the average for unlit side is -153 C.
There is no cooling system on the moon, it rotates and the lit part is constantly changing.
So, the average between the hot side and the cold side would seem to be about -23 C.
Cold.

Yeah, but the lit side is lit for the same amount of time.
I would guess that the part that is rotating out of the sun cools very rapidly.
Then again, the part moving into the sunlit side would warm up quickly in the naked sunlight.
If the moon rotated in 24 hours, would the average temp be different? By how much.

But that is all be side the point…the statement did not mention factors such as rotation rate…just whether or not the atmosphere cools or warms the Earth.
What is the average temp of the Earth?
It is listed as 0.87C for the surface, and a warmer 15C for the atmosphere.
But it does not say whether that 15c is for a particular layer or height, or the whole volume…
Seems unlikely it is for the whole volume, since most of the atmosphere is way up in the sky and very cold.

In any case…the Earth is warmer than the moon, same approximate distance from the Sun.

I have no dog in this hunt, just trying to discern what is being said…

At night under clear calm skies, it cools relatively quickly at Sun set, depending how much water vapor there is, and then late in the morning as air temps near dew point, the atm emits energy stored in water vapor, 4.21J/gm, vs 1J/gm delta C. The lower the humidity is, the less of an impact the regulation has, why deserts cool so much, and why tropics don’t.
But, Min T correlates to dew point just under 98%

Yup…I used to determine how cold it was likely to get by looking at the dew point in the plant nursery days.
Once in a while it cooled below the dew point…I saw that a handful of times in ten to fifteen years.
When every cent you have and will earn for the next year is in a crop, you miss zero nights of observation during the critical periods of the year.
But any wispy clouds would reverse any cooling very quickly…we were saved from spending a lot of money numerous times by a streak of cirrus.

( Minor apologies for the “raw” character of the CoSy code due to it being right at the x86 register level . )

The temperature of a gray body in our orbit , in terms of energy , is about 278.6 +- 2.3 from peri- to ap- helion , about 5c . That appears to be about the standard design temperature for satellite instrumentation modules .

I strongly agree with the comment that the atmosphere and its GHGs massive effect is on variance rather than mean temperature .

Robert, here in Florida in the Winter months, it is often very hot and sunny ahead of a sharp cold front, and sometimes it has been hot and sunny for months on end.
But when that front passes, if the air is dry enough, within a few hours of sunset there is frost on the ground.
Even sooner than this there is frost on the hoods of cars sitting outside…and those cars were hot as the dickens before the front passed and the sun set.
The part of the ground under the surface did not cool off in a few hours, but it is unable to transfer heat to the surface as fast as it is radiating away to space.
Plants outside that cannot stand frost will die.
Unless you put a covering over them…anything at all will do it, even a thin layer of plastic or a bed sheet… as long as it extends to the ground. It will stay plenty warm enough under there to keep those plants alive.
Because that thin layer will prevent radiation from cooling the air under the covering faster than it can radiated up from the ground.
It is amazing how much you can observe by sitting outside all night long with thermometers all over the place.
Near any cement…warm and no frost…those plants live. On top of it or within a few inches.
Under a tree…like the live oaks we have here…warm and no frost…those plants will live.
The effect of heated buildings and trees extends for tens of feet, although it drops off fast once you are out from under the tree or more than a few feet from the building.

“Because that thin layer will prevent radiation from cooling the air under the covering faster than it can radiated up from the ground.”

Should be “radiated up from the ground”
But this not a good description of the heat transfer from the ground to the air under the sheet.
The thermal energy must conduct up from below, to the surface, and then it both radiates and conducts heat to the air under the sheet. I doubt there is much in the way of convection under there.

Nowadays large operations use a type of plastic sheeting that will not conduct heat from the plant surfaces that are in contact with it, rather than a regular sheet of polyethylene, which will allow cold damage to the parts of the plants in contact with the plastic.

Interesting, I also learned a bit about what you are pointing out over the last several years from the two portable greenhouses which I have been using to keep my citrus trees alive through the winter in an area where they could not survive otherwise. It is surprising how effective they are at maintaining enough warmth for survival.

I keep large containers of water in each. I thought that they would aid in holding back the cold, and they appear to have done so. In the one unheated greenhouse the surface water only lightly froze once. That was when outside temps dropped down to the mid 20s F.

Concrete needs a lot more time to cool, Grass, is just an air based insulator, top freezes, ground is still warm for a while.
The sky gets really cold. I had the telescope out a month ago, and it was in the low 40’s about 2:30am, but bitter, clear and calm. Heavy frost on truck, so I got the IR thermo out. Sky was -60F, 100F colder than air temp.A good part of the spectrum is 70 to over 100F colder than concrete temp, all day long. Part does get a lot of GHG spectrum, changes from 3.7W/m^-2 in about 1.8F making -40F, -38.2F(it changes depending the temp, I’ve done the calculations for -40F)Even if the whole rest of the spectrum was air temp, the window would still be quite cold, and conduction from those bands would warm things into the window where it would still cool to space.

Goldminor.
Try spraying some water in there…it will keep it much warmer.
If you have a well, the groundwater will be about the average yearly temp for your location. In Pasco county, that is about 72F.
Now, 72 degree water from overhead misters is very cold on a hot Summer day.
But on a cold night…it is steaming.
I kept most of an 80,000 sq ft shadehouse from ever getting below 50F by turning on the water.
I had the lace set up with drip irrigation, and for most of the plants that was all you ever needed.
But for flexibility, you also need to have overhead irrigation throughout, so you can put in plants that are too small and closely spaced for drip tubes, or occasionally other reasons. Plus i did a foliar feeding every week so that made it easy.
Instead of the rotating kind that throw water a long way in rather large drops, thus minimizing the number of sprinkler heads you need, i set up mist heads on every bay, spaced ten to twelve feet apart in one direction and ever five feet the other.
Then I had a series of zones valves and electromechanical timers connected to solenoid valves that rotated the flow of water into each bay for a few minutes every hour.
We only had two wells and only one was a large deep one. It could pump a few hundred GPM. So I could only turn on about 8 out of about 80 bays at one time.
But the steam (cold steam) spread the heat out evenly.
After about five minutes it was as warm as the water could make it, and the timers rotated the zone valves to the next zones.
So once you have the timers calibrated and synchronized, the water would just spray until it warmed up enough in the morning to turn it off.
For outside stuff, you sprayed with water in the morning to melt frost if it was above 32 (frost forms at 38)
and that was sufficient…the damage is done when the frost melts as the sun hits it…the melting frost takes latent heat from the leaves and burns them.
For temps below 32, you turn it on before it gets to freezing and leave it on until all the ice is melted the next day. Only once or twice did a freeze last into a daytime interval for more than a few hours.
So you have to know the temp everywhere…if it gets too cold and the water in the valves or lines begins to freeze before you open them…you are done for. Nothing you can do.
I knew a strawberry farmer who lost everything he had because him and his wife went to a movie one evening.
As soon as he walked outside and smelled the air, he knew his whole crop and every penny he had was gone. No way to unfreeze pipes and valves. If he could have got the water on, he would have had some damage perhaps, but he would not have lost much.
Anyway…turn some water on if you want it warmer.
Although…citrus takes four hours below 28F for any damage to occur, and cold, but with no damaging levels of cold, sweetens the fruit.

Back in those days, 1980s and 1990s, there was no internet. No twenty four hour weather stations, even if you had cable which rural Pasco did not have.
Weather info was spotty and hard to come by unless you paid for it. Some did, but even then most info was gleaned from observations made in real time on the spot.
There was a weather station with a weather fax machine on the roof of the USF College of Social and Behavioral Sciences building , but it was 30 miles away and was little use in the middle of the night anyway. They never did give me a key.

@ Menicholas…Thanks for the added info. These are small greenhouses, 12’x7′. They tend to stay moist inside on their own. Perhaps that is why they hold back the freeze as you suggest “..Try spraying some water in there..”. I was happily surprised to note that they had that capability. There is a 30 gallon tub of water in each, and the only ice that developed a few times was no more than a 32nd”, whereas a bucket of water sitting outside had almost 2 inches of ice overnight.

“Another article stated that if the lower atmosphere warms, the upper atmosphere must cool, which makes no sense to me.”

It makes no sense to me either. Reading back posts of “Realclimate”, it looks like Gavin Schmidt was
“schooled” on this issue.
James B. Shearer says:
27 Feb 2005 at 6:51 PM
Eli, Gavin is arguing above that adding greenhouse gasses would cause the stratosphere to cool even if the stratosphere was not being warmed by the adsorption of UV and that this is the explanantion of stratosphere cooling. I am arguing that this is incorrect. If all warming was from below there would be no cooling.
Gavin, the gradient increases but the fixed point is the top of the atmosphere not the effective radiating level. As a result all layers warm with the amount of warming increasing as you move towards the surface. This means the effective radiating level rises.
Consider the top of the atmosphere as an arbitrarily thin gray body. Looking down from this layer we see the earth radiating at its black body temperature, TB. Looking up we see space at near absolute zero. So this layer will have temperature ((TB**4)+0**4)/2)**.25 or (.5**.25)*TB or .84*TB as claimed above. If the top layer is not arbitrarily thin but instead has emissivity e then its temperature will be TB*(2-e)**(-.25). In either case the temperature is independent of the details of the temperature structure below, the key point is that the total outgoing radiation must balance the incoming solar radiation.
[Response: Obviously radiaitve balance must be maintained, and I am not disputing that the effective radiative level will rise. Possibly, the solution to this is that in the real atmopshere the movement of this level is severely constrained (mainly by adiabatic cooling) and so cannot rise enough to produce your solution. I’ll think about this a little more…- gavin]

Leo Smith: Another effect of high altitude air traffic could be the soot produced by gas turbines depositing on clouds below, reducing their albedo.This theory was suggested by the late Professor D.K.Edwards who was a leading radiation heat transfer researcher. He also suggested that jet-setters bump along below 15,000 ft !

The Sun is much wider than the Earth, but also very far away. The limbs of the sun thus illuminate a little air above the portion of the surface that is unlit.
Plus, some of the light from the sun is bent inward towards the center of the Earths shadow.
This is why during even total lunar eclipses, the moon is still visible. Do you want to count that light and the air it passes through?
You might get an answer if you calculate the percentage of the time after sunset and before sunrise that constitute twilight as it relates to the entire nighttime period.
It is a lot of it, but it varies with latitude and season.
And then there are several types and definitions of twilight…civil, nautical, astronomical…
I al gonna stick with a little bit more than half.

Here is the shadow of the Earth, BTW, plainly visible during twilight. The grey part is the full shadow, the pink band is the Belt of Venus:

We have heard many times that there is not a good or detectable relationship between solar activity and global temperature. The proxy normally used is 10Be in soil.

Is there a good proxy for solar IR strength that is separate from both sunspots and 10Be?

If the upper atmosphere is very hot it surely radiates downwelling IR which is captured by water vapour and to a much lesser extent, CO2. That contributes to systemic warming. Creating O3 high in the atmosphere also contributes to warming. How does O3 warming compare with CO2 warming?

Prof Lu of Waterloo U holds that the O3 warming (or not) strongly affects the global temperature, particularly over Antarctica where the O3 fluctuation is large.

If the UV is not absorbed along the way down, it reaches the surface or the surface of a cloud. What then? How much is reflected back into space?

All things considered the combination of O3 creation and direct warming from the highly variable UV and EUV (100:1) points to a viable mechanism for producing significant changes in the temperature at ground level.

Charles You say “One recent article by NASA says that the Thermosphere (above 100,000 ft) has cooled in recent years due to decreased solar activity and a reduction in ultraviolet light. ”
This fits very well with Figs 3,4,5 6,7,8,9,10 and 11 in my recent paper which says that the millennial temperature cycle peaked at about the end of the 20th century. Fig 11 provides a particularly obvious example.

Climate is controlled by natural cycles. Earth is just past the 2004+/- peak of a millennial cycle and the current cooling trend will likely continue until the next Little Ice Age minimum at about 2650.See the Energy and Environment paper at http://journals.sagepub.com/doi/full/10.1177/0958305X16686488
and an earlier accessible blog version at http://climatesense-norpag.blogspot.com/2017/02/the-coming-cooling-usefully-accurate_17.html
Here is the abstract for convenience :
“ABSTRACT
This paper argues that the methods used by the establishment climate science community are not fit for purpose and that a new forecasting paradigm should be adopted. Earth’s climate is the result of resonances and beats between various quasi-cyclic processes of varying wavelengths. It is not possible to forecast the future unless we have a good understanding of where the earth is in time in relation to the current phases of those different interacting natural quasi periodicities. Evidence is presented specifying the timing and amplitude of the natural 60+/- year and, more importantly, 1,000 year periodicities (observed emergent behaviors) that are so obvious in the temperature record. Data related to the solar climate driver is discussed and the solar cycle 22 low in the neutron count (high solar activity) in 1991 is identified as a solar activity millennial peak and correlated with the millennial peak -inversion point – in the RSS temperature trend in about 2004. The cyclic trends are projected forward and predict a probable general temperature decline in the coming decades and centuries. Estimates of the timing and amplitude of the coming cooling are made. If the real climate outcomes follow a trend which approaches the near term forecasts of this working hypothesis, the divergence between the IPCC forecasts and those projected by this paper will be so large by 2021 as to make the current, supposedly actionable, level of confidence in the IPCC forecasts untenable.”

.Fig 12 provides the cooling forecast out to 2100.

Fig. 12 compares the IPCC forecast with the Akasofu (31) forecast (red harmonic) and with the simple and most reasonable working hypothesis of this paper (green line) that the “Golden Spike” temperature peak at about 2004 is the most recent peak in the millennial cycle. Akasofu forecasts a further temperature increase to 2100 to be 0.5°C ± 0.2C, rather than 4.0 C +/- 2.0C predicted by the IPCC. but this interpretation ignores the Millennial inflexion point at 2004. Fig. 12 shows that the well documented 60-year temperature cycle coincidentally also peaks at about 2004.Looking at the shorter 60+/- year wavelength modulation of the millennial trend, the most straightforward hypothesis is that the cooling trends from 2004 forward will simply be a mirror image of the recent rising trends. This is illustrated by the green curve in Fig. 12, which shows cooling until 2038, slight warming to 2073 and then cooling to the end of the century, by which time almost all of the 20th century warming will have been reversed.

As has been pointed out before here several times previously, the data since 2008, from which the forecast period on Fig. 12 runs, has already demonstrated both yours and Akasofu’s predictions to be wrong. The blue line has continued on a trajectory much more closely aligned to the IPCC forecast; in fact, a little on the high side of that as of end 2016.

See this Fig and a response posted on an earlier threadhttps://wattsupwiththat.com/2017/05/25/no-santer-et-al-have-not-refuted-scott-pruitt/#comment-2511654
and my reply
My main reason for showing the Akasofu curve was to show an example of an interpretation which at least honors the 60 year cycle which clearly exists over the last century. Here is my paper’s Fig 4 detailed interpretation as of end 2016 which shows the 2016 El Nino as the temporary deviation from the cooling trend which it most likely is.
The RSS cooling trend in Fig. 4 and the Hadcrut4gl cooling in Fig. 5 were truncated at 2015.3 and 2014.2, respectively, because it makes no sense to start or end the analysis of a time series in the middle of major ENSO events which create ephemeral deviations from the longer term trends. By the end of August 2016, the strong El Nino temperature anomaly had declined rapidly. The cooling trend is likely to be fully restored by the end of 2019.

The RSS cooling trend in Fig. 4 and the Hadcrut4gl cooling in Fig. 5 were truncated at 2015.3 and 2014.2, respectively, because it makes no sense to start or end the analysis of a time series in the middle of major ENSO events which create ephemeral deviations from the longer term trends.

As Nick Stokes pointed out on the previous thread you linked to, global temperatures in 2009, 2010, 2011, 2012, 2013 and 2014, all of which occurred prior to the onset of the recent big El Nino, were all warmer than 2008, the supposed start of yours and Akasofu’s cooling trend.

Not only that, all of those years occurred during the weakest solar cycle in living memory and one of them, 2011, was also dominated by strong La Nina cooling conditions. What do you suggest was the reason for this, given that your prediction was for cooling and all normal climate forcings, apart perhaps from enhanced greenhouse forcing, were also indicating cooler conditions?

99% of the atmospheric mass is below 32 km. It’s these molecules that make conduction, convection, latent heat process possible, the processes that actually run the atmospheric heat engine. Above 32 km the lack of molecules mean radiation is the only mode of energy/heat movement. Without molecules, energy, heat, hot, cold terms and concepts fall apart.

In the end of the blog is a common mistake that the sun does not heat up the atmosphere. It does. The SW radiation absorbed by the surface is 167 W/m2 and the atmosphere absorbs 72 W/m2, together 239 W/m2. The main absorbing gas is surprise, surprise .. water 77 % and ozone 20 %. The LW radiation emitted by the Earth is absorbed by water 81 % and by CO2 13 %. And by the way, the absorption of CO2 happens below 1 km altitude.

It seems likely that after the SO2 related affects of Pinatubo dissipated in the mid 90’s, there was some type of change that occurred in the Stratosphere, it cooled below the pre eruption temperature levels by almost 0.5 K and has been flat ever since.

Nice write up…you may want to check your analysis software. The RAOB data looks fine.
I went to ruc.noaa.gov site & collected a years worth of Tuscon, Az for 2003 where your 00Z/12Z data was converged. Just looking at the tabulated data for 100mb, for example, shows temps varied quite a bit with extremes larger than your graph allowed. Below is 00Z Jan 1 to 12Z Jan 15.

It seems that the increased volcanic activities in severity from the 1990s may have cause and effect for the temperature and CO2 ballance. When the Aerosol Gases and ash spread into and around the atmosphere by the jet streams as they raise. I don’t have access to the data for those gases or in the levels above what would effect the data in your article. I’m looking at the correlations of the volcanic activities and the over 18 year’s of stalled temperature increase and how your Arizona temperature/CO2 is nearer the Equator started converging and how long it took for the convergence in Alaska. Temperature decreases seem to trend after volcanic activities throughout our history and the CO2 ppm doesn’t seem to correspond to those changes. The larger the volcanic activities the more earth cools. And yet there seems to trend that the higher the CO2 the longer it takes to cool the lower levels.

I haven’t read the comments thoroughly so apologies if this was mentioned, but my instinct for the difference in the years where the data converge is possibly due to instrumentation. I’m an electrical engineer and in a previous job helped develop balloon launched radiosondes and actually tested with NOAA. Is it possible that the make or model of the radiosonde has changed and that the stock of each location was used up at different rates? At the time they were using a Mark IV radiosonde (the manufacturer escapes me now). That implies that there was at some time a Mark III, II and I, right? Could the different models have different upper level temperature characteristics? In our testing I’ve seen that heat from the RF transmitter in the radiosonde can have an effect on upper air temperature measurements and in earlier models it may have skewed the data collection. Just a thought…

If by any chance aircraft were responsible, there would be no need to do anything since warming is beneficial .
We would know that we could always turn the knob down in the future when the temp was perfect.

What i see …. there is no convergence. There is a step change at 1996. There is no convergence before that, and there is no divergence after the lines magically come together. Makes me think there is a problem with this data.

I would think that the temperature of the atmosphere is directly related to a combination of heat source relative location and local extinction range of LWIR. At some point the extinction range becomes infinite and the radiation leaves the earth system. Secondarily atmospheric density is related to altitude and so to should be extinction range and with it absorbtion and re-radiation. Thirdly, as you go higher in elevation more of the horizon is exposed and less of the downward radiation is directed toward terrestrial objects not to mention the surface being beyond the extinction range of CO2 molecules, so less energy is available to (re)heat the surface.

I found the effect in the surface record in 1996 as well. It has a strong latitudinal component, I think it’s ocean cycles. N20-N30 the Temp in F response to 1 watt of clear sky day solar. These are from surface stations. and if you follow my name there’s a lot more graphs with regional looks at measured surface data.

The equilibrium temperature of a radiantly heated object is a function of the correlation of its absorptivity=emissivity spectrum with its source and sink spectra , eg the spectrum of the earth as seen from space and the power spectrum of the 5.5-e6 of the celestial sphere covered by the Sun’s disk and the rest at so near 0 it macht nichts . See http://cosy.com/Science/warm.htm#EqTempEq .

The change in our spectrum as seen from outside due to additional CO2 at these levels is de minimis .
And no spectral effect can explain why the bottoms of atmospheres are hotter than that calculated on the basis of the spectrum as seen from outside .

Interesting observations. I have a problem with this: The sun is the main driving force for changes in temperature at high altitudes, less so for high latitude locations.
For high latitudes the sun travels more of the atmosphere, than at lower latitudes, where it just passes through. Just a thought.

The upper atmosphere is poorely known and the up-down mechanisms as well.
In fact, many research have pointed out that the upper atmosphere, (Stratophere, Mesosphere, Thermosphere), is cooling since the late 70s/beginning of the 80s (Same time as the ENSO shift). In those times, the sun’s activity was not so low as it is currently, altought it has been proven that the sun’s activity has a tremendous effect on thermospheric temperatures and more relatively one the mesosphere/stratosphere.
So what is the cause of that cooling ? The sun has surely a role in the last decade but prior to that ?

The only interesting theory that i found is that this cooling could have been produced by the ENSO shift, changes of wind patterns and gravity waves. Here is the study :

“Manabe and Wetherald [1967] first showed that an increase in CO2 content in the atmosphere would heat the atmosphere below about the tropopause (by absorbing IR radiations from the ground) and cool the atmosphere above that level (by radiating thermal energy to space). Roble and Dickinson [1989] calculated the degree of cooling above 60 km altitude that one would expect for a doubling of greenhouse gas content at that altitude. They estimated a global mean cooling of 50 K near 350 km altitude. Holt and Zhang [2008], however, in considering the 1978–2007 database of incoherent scatter radar measurements of ion temperature collected at 375 km above Millstone Hill (43 ı N, 289 ı E), found a noontime cooling rate of 47 K per decade, or a 141 K decline over the span of their measurements. As the CO2 concentration increased only 12% during this time period, the simulation would estimate only an 6 K decline. Donaldson et al. [2010] conducted an independent analysis of the 1966–1987 Saint Santin (45 ı N, 2 ı E) radar database and confirmed the Holt and Zhang [2008] finding. In light of this stark factor-of-20 disagreement between theory and observation, processes other than CO2 cooling have been sought to explain the observations. Based on the Saint Santin data, Walsh and Oliver [2011] suggested some agency of O3 as the cooling source, based on the coincidence in time between the beginning of the temperature decline and the beginning of a strong decrease in O 3 content in the lower atmosphere. Laštovicka [2012] noted, however, that the longer 1978–2007 Millstone Hill data showed that the
temperature continued to decline beyond 1994, when the O3 content began a long recovery. [ 3 ] During our efforts to identify the cause of the great temperature decline in the thermosphere, we have noticed a correlation between the behavior of that temperature and the behavior of ENSO (El Niño–Southern Oscillation) activity, both in the timing of an onset of change, a subsequent linear trend, and decadal variations about that trend. This recognition has led us to ask if gravity waves, produced by wind action over the oceans and propagated to the upper atmosphere, may be responsible for cooling that upper region. Recent simulations [e.g., Yigit and Medvedev, 2009] show that gravity waves are expected to cool the thermosphere on the order of 100 K, the order of long-term cooling observed. We know of no other agency capable of cooling the thermosphere by that amount long term.”

“Why is the cooling so much larger than expected, (2) why has the cooling lasted so long, and (3) why is the thermospheric density response to the cooling so small? We have speculated that gravity waves may have caused this cooling, based on recent simulations that show that gravity waves are expected to cool the upper thermosphere by an amount comparable to the long-term cooling observed. A gravity wave proxy formed from the nontidal fluctuations in T° ion showed a positive long-term trend throughout its timeline, consistent with the increasing cooling observed. Fluctuations of T° ion about its long-term trendline were seen to anticorrelate both with fluctuations in the gravity wave proxy and with decadal fluctuations in El Niño–Southern Oscillation (ENSO) activity. The time scales of the long-term trend and the decadal fluctuations are characteristic of the ocean, not the atmosphere. We have suggested that the following scenario may explain these behaviors: (a) the climate regime shift of 1976–1977 launched slow Rossby waves across the oceans, waves which continue to propagate to this day; (b) winds over this increasingly corrugated ocean have launched increasing fluxes of gravity waves into the atmosphere; (c) these increasing fluxes of gravity waves have propagated to the thermosphere to produce increasing amounts of cooling; and (d) the decadal increases in winds associated with the decadal increases in ENSO activity have produced decadal increases in gravity wave fluxes, which, in turn, have caused decadal cooling in the thermosphere. The strong thermospheric cooling seen would be expected to produce thermospheric density declines much larger than those observed via satellite drag if the density at the base of the thermosphere were unchanging. We have noted that a lowering of the turbopause by about 4 km would raise atomic oxygen densities and completely compensate for that large expected density decline at 350 km altitude and referenced evidence of that lowering. We have asked if the heat pumped by gravity waves from the upper thermosphere to the lower thermosphere may augment the positive temperature gradient in the turbopause region, thereby making it more stable against the development of turbulence, and hence lowering the turbopause itself. Our proposed answers to our three posed questions are that the magnitude of the cooling is due to the agency of atmospheric gravity waves, that the length of the cooling is due to agency of ocean Rossby waves, and that the small density response is due to the lowering of the turbopause.
The ocean effect is a long-term transient response to forcing of unknown origin. The atmospheric effect is a steady state response to ocean forcing. This scenario may have validity, but it is unproved. The ocean Rossby wave source is purely speculative. Those Rossby waves, if they should exist, cannot be detected amongst the larger ocean eddies with current observational capabilities. (We ask if the very smallness of these ocean waves may be essential in that it leads to atmospheric gravity waves that are able to propagate to the upper thermosphere without growing to their breaking amplitude and dissipating at lower altitude.) For the existence of increasing amounts of gravity waves in the thermosphere, however, we have the evidence from our data of the increasing amounts of nontidal fluctuations in temperature. If the theorists and modelers [e.g., Walterscheid, 1981; Yi ̆git and Medvedev, 2009] are correct, this increasing gravity wave flux should increasingly cool the thermosphere. 42 ] These speculations need broad vetting by additional studies based on other data sets and of applicable theory. [ 43 ] We believe that the magnitude of the thermospheric temperature decline has been so great that the CO2 theory of its cooling cannot be maintained. It is certainly possible, however, that increased greenhouse warming at surface level has initiated the train of events that has led to the cooling by others means.”

A similar question relating to temperatures at different altitudes has been investigated in tge southern hemisphere by Erl happ. Focuses on observations not models. https://reality348.wordpress.com. Chapter 6 highlights temperature divergence in winter but none in summer, despite decades passing. So Well mixed CO2 cannot choose when to emit IR but highly variable ozone might if the polar vortex lowers the tropopause closer to ground level.

Greg posted “Well if it starts at the surface, why is it called UPPER atmosphere? Who defines it in that way apart from the author?”

I have worked in weather related activities for almost 70 years and 36 of those at what was, and is, called Upper Air Stations, even though they are on the ground.

One fellow criticized me for the statement: “Another article stated that if the lower atmosphere warms, the upper atmosphere must cool, which makes no sense to me.” My problem with that was the MUST part of the statement.

Here is a direct quote: Jeffrey Masters, Ph.D. — Director of Meteorology, Weather Underground, Inc. “Climate models predict that if greenhouse gases are to blame for heating at the surface, compensating cooling must occur in the upper atmosphere. We need only look as far as our sister planet, Venus, to see the truth of this theory. Venus’s atmosphere is 96.5% carbon dioxide, which has triggered a run-away greenhouse effect of truly hellish proportions. “

I did this little study because I was interested in the results, I don’t get paid, I have no grants, just me.
Since this is a follow up, I added three more stations to the list of stations where the diurnal temperatures aloft have converged. San Diego, California in 2010, Dodge City, Kansas in 2009, and Brownsville, Texas, also in 2009.